We have been looking at adding a woodstove since we bought this house three years ago. Last winter was the breaking point. I did a cost benefit analysis. Our heating last winter was $2600 and our electrical increases by $100/month through the winter thanks to additional space heaters. My goal was to eliminate all but back up propane use, and allowed for evening use of space heaters as needed.
We purchased a Napoleon 1400PL, and will have the chimney go straight up through the ceiling and the second floor, where it will be walled in with a top and bottom vent cut into the walled in portion then through the roof, hopefully scavenging some heat there as well. There will be a cast iron vent through the heated room ceiling to the second floor and two more ceiling fans. My forced air furnace runs the fan every 15 minutes even when not heating per programming. We suffer black outs here as well, so when it's well below zero, I have to power up the generator to run a space heater or two to keep a room or two warm. The woodstove is the solution that doesn't need power.
The total cost for stove install and fans vents and misc is $5200. I recently purchased enough wood to get through winter on a 24/7 burn. I estimate a 3-4 year ROI, with the bonus of emergency heating. Possibly faster depending on the severity of the next few winters. My future wood will be free as my very good neighbour works for Hydro clearing trees, and will have the trucks drop the wood in my driveway for self processing, which saves them work clearing and disposing of the wood.
So, there we are, this is why I did it, now, just waiting for the install!
Now, really sit down and figure out why you want to do this. To be honest, just because you have the money and like the romantic thought of a nice fire on a cold day, isn't a great reason. Unless you are rich of course. Woodstoves are a tonne of work, and require a lot of sweat equity that I didn't calculate. However I don't ever buy the 'how much is your time worth' argument. Nobody gets paid to sit in front of the tv instead of going out and chopping wood after work.
Ian